Lectures 15 & 16

Question 1

Meteorite

Answer 1

Are samples of solid planetary bodies in our Solar System

Question 2

Meteoroid

Answer 2

A meteorite before it reaches the Earth’s surface

Question 3

Meteor

Answer 3

The atmospheric phenomenon created by a meteoroid in transit through the atmosphere

Question 4

Asteroid

Answer 4

A small, rocky, or metal-rich planetary body orbiting the Sun

Question 5

Parent Body

Answer 5

The solid object from which the meteorite originated

Question 6

Fall

Answer 6

A recoverable meteorite whose fall to Earth was witnessed

Question 7

Find

Answer 7

A meteorite that was discovered sometime after its fall

Question 8

What happens when a meteorite falls

Answer 8

When they enter the Earth, the atmosphere causes friction on the meteorite causing some parts, or all of it, to burn up

Question 9

Main sources of meteorites

Answer 9

Asteroid belt*, some from the Moon, some from Mars

Question 10

Chondrite meteorites

Answer 10

Undifferentiated. Represent rapid heating and cooling of dust in the solar system nebula

Question 11

Achondrite meteorites

Answer 11

Differentiated. Represent igneous magmas

Question 12

Significance of meteorites

Answer 12

Meteorites tell us the age and origin of the solar system and also the geology of the asteroid (timing and ages of events)

Question 13

Albedo

Answer 13

A measure of reflectance of an object

Question 14

Main results of the exploration of Vesta

Answer 14

• The impact basin, Rheasilivia, has a central peak that is more than twice the height of Mt. Everest.
• Has a core of ~200 km and has a mantle and crust

Question 15

Main results of the exploration of Ceres

Answer 15

• Has lots of water ice
• Partially differentiation
• 4 km high mud cryo-volcano (Ahuna Mons)

Question 16

Significance of asteroids

Answer 16

They provide insight into the origin and evolution of the solar system including the geology of small bodies

Question 17

Two missions currently exploring asteroids, the asteroids they are exploring, and the space agencies involved in each mission

Answer 17

• OSIRIS-Rex (Bennu, NASA)

- Hayabusa2 (Ryugu, JAXA)

Question 18

Importance of asteroid sample return

Answer 18

• Select samples from known parent bodies with context

- compare properties of meteorites to identify possible common parent bodies/processes

Question 19

Describe how HED meteorites are linked to the asteroid Vesta

Answer 19

Howardites are a mixture of Eucrites and Diogenites.

• Eucrites are hardened lava that flowed on Vesta’s surface
• Diogenites come from rock buried deeper down in Vesta’s crust